I seem to remember a similar story a few years back. The hacker in question actually built his antenna into his clothing, and walked around Target, pressing a button occasionally when standing near another customer. I don’t remember whether he ever got caught.

What I’d like to see next is the reverse–a way to unstick a stuck shopping cart.

Keep pushing it around until the cover grinds away and you get back to wheel again.

@Mohonri
Didn’t RTFA? It clearly explains that unlocking is accomplished by sending a continous 8kHz signal.

That’s interesting. I would have guessed that the unlocking signal would be more complex than the locking signal…

Bubbles isn’t going to like this…

There are shopping cart thieves???

Bubbles?

As in Bubbles of Austin TX. Bubbles?

He’s the only Bubbles I know of that is connected to shopping carts.

“He found an 8 kHz signal at a 50% duty cycle at 30 ms intervals (it would be hard to make a better case for why you need an oscilloscope).” — Mike Szczys

derp, you don’t need a scope for that.
you can measure that with a decent multimeter.

Bubbles can rest easy not seem to have shopping carts like those in Baltimore

FTA: “The system can be defeated, however it is unlikely that the kind of person that steals shopping carts would be inclined to develop an unlocking transmitter”

… with the exception of the author, I assume ;-)

Once while living in an urban center, there were so many abandoned ‘stolen’ carts left in front of my residence that I decorated them with xmas lights during the holidays (apparently individuals hired to retrieve them did not care for those carts left mangled, embedded within snow banks by the plows).

@Mohonri I am pretty sure that I read the same article, trying to remember where tho

I think 8 Hz is the frequency the security alarms on the doors use. At least that was the case at a Walgreens I worked at. I guess the shopping cart security system is a 1000 times more awesome.

friend found some shop lifting tags in the parking lot of our mall. they had sirens built in and were sounding, they had been cut off something.
they had texas instruments MSP430-F2001 processors, a 58khz tuned coil, battery, peizo, 2 switches, led, smt parts. They used a spring loaded pin to lock the device. Magnet to unlock.
Case is glued closed.

As the controller is likely locked, desoldering to try to read will likely be pointless.
What should my friend do with these?
Strip it and toss the rest?

I invented this technology back in the mid 90′s. If you look up my name in the patent office you will see my patents. This particular model is a copy cat of my original product for Gatekeeper systems. Carttronics just copied much of the design except the goofy shovel like brake. The references to the 8khz locking signal were half right. The carrier is digitally encoded at at a low data rate. The carrier frequency was chosen to be under FCC part 15 regs. I also created the PURCHEK anti roll-out technology.